There is conventionally known an electro-photographic type image forming apparatus such as a laser printer and an LED printer. One such image forming apparatus uses a developing cartridge including a developing roller for supplying toner. Prior art discloses a developing cartridge attachable to a drawer unit. The drawer unit is configured to be accommodated in the image forming apparatus and pulled out from the image forming apparatus. The drawer unit includes a photosensitive drum. The developing roller faces the photosensitive drum upon attachment of the developing cartridge to the drawer unit.
Another prior art discloses a developing cartridge configured to be attachable to a drum cartridge including a photosensitive drum. The developing roller faces the photosensitive drum upon attachment of the developing cartridge to the drum cartridge. The developing cartridge is attached to an image forming apparatus in a state where the developing cartridge is attached to the drum cartridge.
Further, a developing cartridge including a storage medium is known. An IC chip is one example of the storage medium. The storage medium has an electrical contact surface. The developing cartridge includes a holder for retaining the storage medium, and a coupling.